/Engine/Source/Runtime/Core/Public/Math/RotationMatrix.h
Builds a matrix with given Y and Z axes. Y will remain fixed, Z may be changed minimally to enforce orthogonality. X will be computed. Inputs need not be normalized.
static [TMatrix](API\Runtime\Core\Math\TMatrix)< T > MakeFromYZ ( [TVector](API\Runtime\Core\Math\TVector)< T > const & YAxis, [TVector](API\Runtime\Core\Math\TVector)< T > const & ZAxis )